I remember this feature at the old tradesports, I've never tried matchbook but I wonder if any books allow you put a "limit order" on in-game betting. What I mean by that is for example if you only want to take Federer at odds of -110 or better you could put a limit order for "Federer -110" with the in-game betting software of the book. Your limit order would automatically be placed when/if the odds ever got to "Federer -110".
I don't see why all books wouldn't want this because it would only increase the amount bet and isn't that what they all want?